foreach $f (@files) {
  open FILE, $f or die "Error: $!";
  while(<FILE>) {
    chomp;
    my ($k,$v)=split("=",$_,2);
    # Assume dn= comes before other lines
    $level1=$k, next if $k eq "dn";
    unless ($level1) {
      die "Need to get dn= line first\n";
    }
    push @{$hash{$level1}{$k}}, $v;
  }
  close FILE;
}